port: different names for pal and jpn EXEs

Makefile.port

@@ -100,12 +100,15 @@ TARGET_BIG_ENDIAN = 0 # TODO
 
 # The VERSION constant is used in the source to handle version-specific code.
 ifeq ($(ROMID),ntsc-final)
+  BIN_NAME = pd.exe
   VERSION = 2
   IS_PAL = 0
 else ifeq ($(ROMID),pal-final)
+  BIN_NAME = pd.pal.exe
   VERSION = 4
   IS_PAL = 1
 else ifeq ($(ROMID),jpn-final)
+  BIN_NAME = pd.jpn.exe
   VERSION = 5
   IS_PAL = 0
 else
@@ -257,7 +260,7 @@ LDFLAGS := $(TARGET_LDFLAGS)
 # (We use this a lot)
 export ROMID
 
-BIN := $(B_DIR)/pd.exe
+BIN := $(B_DIR)/$(BIN_NAME)
 
 default: $(JSON_HEADERS) $(BIN)